I have a ford focus 2004 1.6 there's a button i want to ask what it does?

I have a button the gear stick i want to ask if anyone knows what does it do? I pressed it and i felt the car got boosted, wanna make sure if it is okay to press it, i mean why would ut not be there if it was not to press

It is the Overdrive button. When you push it the transmission shifts OUT of OD and to a lower gear so it feel more peppy and it won't go back into overdrive gearing until the button is released. You can leave it off around town but when you hit the highway re-engage the OD so you get better fuel mileage, but no harm no foul if you leave it off. (Read about it in your Owner's manual).

Change one gear back for more power. Eg Up a hill.
Peace.

It's likely the overdrive button. When OD is on the rpms get lower for fuel economy. When it's off the rpms stay higher and in the power range.